1. Field of the Invention
The present invention relates to a driving control device for controlling automatic driving of a vehicle by controlling the vehicle speed and automatic steering corresponding to a planned route based upon the set planning route, the current position of the vehicle on the planning route, and the current route of the vehicle.
2. Description of the Related Art
In recent years, navigation devices are widely used for vehicles, which employ a Global Positioning System (GPS) for detecting the position of the vehicle based upon the position data received from artificial satellites. Furthermore, various techniques have been proposed and put into practical use, wherein driving of the vehicle is controlled based upon the vehicle-position information obtained by the GPS, forward road information obtained by a camera or the like, and so forth.
For example, a technique is disclosed in Japanese Unexamined Patent Application Publication No. 10-76964, wherein information with regard to the road ahead of the vehicle (painted line on the road) is detected with a CCD camera, and the steering angle is determined based upon determination results of the moving direction of the vehicle in order to automatically control a steering device. During the automatic steering driving, in the event that the distance between the future position of the vehicle of a predetermined distance ahead of the current position thereof and the painted line.(i.e., lateral deviation) exceeds a predetermined threshold, the system determines that any abnormal situation occurs and that whether the automatic driving mode can be cancelled or not. In this case, the automatic driving is maintained until the system making a determination that the automatic driving mode can be cancelled from the time of the system making a determination that the automatic driving mode cannot be cancelled.
With the aforementioned technique disclosed in Japanese Unexamined Patent Application Publication No. 10-76964, the system determines occurrence of abnormal situations only based upon the amount of lateral deviation. However, in many cases, control error causes fluctuation of the lateral deviation, and accordingly, precision in detection of true abnormal situations is greatly affected by tuning of the device, posing a problem of stability and accuracy of the driving control.
The present invention has been made in order to solve the aforementioned problems, and accordingly, it is an object thereof to provide a driving control device for detecting abnormal situations during automatic driving with high precision based upon the control error and the intent of the user so as to control driving of the vehicle according to the intent of the user.